Published 10:00 pm, Thursday, July 29, 2004

Researchers at the University of Washington have received $30 million, the largest grant ever awarded by the Environmental Protection Agency, to study a suspected link between air pollution and cardiovascular disease.

The 10-year study will follow 8,700 people in six states to determine whether breathing tiny particles spewed by belching car engines, burning coal and diesel fuel hardens arteries and causes a spike in heart attacks and strokes on especially polluted days.

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The microscopic specks -- less than one-thirtieth the width of a human hair -- are known to aggravate asthma and other chronic lung conditions.

But it's unclear how extensively they contribute to heart disease.

Previous studies of the health effects of pollution have focused on lung disease and logged heart attacks and strokes as a secondary priority.

But a growing body of evidence points to cardiovascular disease as an even more common consequence of dirty air, Kaufman said.

"It appears from past studies that the overwhelming amount of mortality (caused by air pollution) is due to heart disease rather than lung disease," Kaufman said. "That's what's been sort of a surprise in the literature so far."

At a news conference announcing the grant yesterday, EPA Administrator Mike Leavitt pointed to the hazy Seattle sky, fed by wildfires in British Columbia and Eastern Washington.

"We can't see Mount Rainier because of an accumulation of particulate matter," Leavitt said. "We need to know what happens when those particles get into our lungs."

The study subjects, ages 50 to 89, will undergo tests to measure the buildup of plaque in their arteries. They will also be monitored for heart attacks and strokes.

The participants live in nine communities in California, Illinois, New York, North Carolina, Maryland and Minnesota and were originally recruited for a study of atherosclerosis -- or hardening of the arteries -- also coordinated at the UW.

Nine other universities will help track participants and collect data.

The UW received a total of $954 million in research grants last year, including a $50 million grant from the National Institutes of Health to study infectious diseases, according to Craig Hogan, vice provost for research.

In June, the American Heart Association issued its first statement acknowledging the mounting evidence linking cardiovascular disease and air pollution.

"This grant is encouraging because it might help determine the extent of that risk," said Kristen Richmond, spokeswoman for the American Heart Association. High.

For now, high cholesterol and second-hand smoke are still considered greater risk factors for cardiovascular disease, she said.

Still, there's evidence of health problems occurring at even lower levels than the national standard, McLerran said. The UW's study could end up strengthening the argument for tighter standards, he said.

"Identification of what levels begin to cause those problem is something that will be extremely helpful as new regulations and new thresholds for regulations are being established," McLerran said.